JOHANNESBURG, SOUTH AFRICA - JULY 15: A mine dump of fine sand, the residue of crushed rock from deep mining, is eroded by the elements on July 15, 2013 in Johannesburg, South Africa. Johannesburg became the centre of gold mining in 1886 when gold was first discovered. Two government officials were sent to establish a settlement and named it Johannesburg after the first name they both shared. The gold rush lasted for over 100 years. The South African mining industry has shed more than 340,000 jobs since 1990 but is still the fifth largest gold producer in the world and has vast amounts of other minerals still to be unearthed.. (Photo by Christopher Furlong/Getty Images)